1. Field of the Invention
The present invention relates to a process for the solubilization of salicylic acid derivatives in at least one vegetable oil, and to cosmetic and/or dermatological compositions containing such a solubilized salicylic acid derivative. Such compositions can be used for treating the body and face, including the scalp and nails, and more especially for treating acne and skin ageing (wrinkles, fine lines, complexion). The present compositions can take the form of emulsions, oily solutions or dispersions of lipid vesicles.
2. Discussion of the Background
It is known to use salicylic acid derivatives as keratolytic agents for treating acne and as anti-ageing agents in cosmetic and/or dermatological compositions. Thus, FR 2,581,542 and EP 378,936 describe such derivatives.
These derivatives are of great importance on account of their biological effects on the skin. However, their use creates a problem, since they occur in crystalline form and are soluble neither in water nor in the oils traditionally used in the cosmetics field, such as mineral oils (petrolatum, paraffin). Thus, if such salicylic acid derivatives are introduced "as is" into cosmetic and/or dermatological compositions, they remain in the crystalline state, making the use of the composition containing them ineffective for treating the skin.
These derivatives are, on the other hand, soluble in lower alcohols such as ethanol or isopropanol, or in solvents such as octyldodecanol, some glycols, short-chain (&lt;C.sub.12) fatty alcohols or short-chain (&lt;C.sub.12) esters. Lower alcohols have the drawback of drying and irritating the skin, and it is hence preferable to avoid using them in body and/or face care products. Short-chain fatty alcohols and fatty esters and some glycols which enable these salicylic acid derivatives to be solubilized result in the penetration of active agents into the skin, which is not necessarily desirable in skin care products. Moreover, at the present time, there is, generally speaking, an increasing endeavor to limit the use of solvents in skin care products, since these solvents are not always well tolerated and can bring about irritation when used in excessively large amounts.
Thus, there remains a need for a method of solubilizing salicylic acid derivatives which overcomes these drawbacks. There also remains a need for cosmetic and/or dermatological compositions which contain solubilized salicylic acid derivatives.